Measurement of QED structure functions of the phot

Authors: OPAL Collaboration

Publish Date: 2014/03/31

Volume: 74, Issue: 1, Pages: 49-55

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Abstract

We have studied azimuthal correlations in singlytagged e+e− → e+e−μ+μ− events at an average Q 2 of 52 GeV2 The data were taken with the OPAL detector at LEP at e+e− centreofmass energies close to the Z0 mass with an integrated luminosity of approximately 100 pb−1 The azimuthal correlations are used to extract the ratio F Bαmma/F 2αmma of the QED structure functions F BαmmaxQ2 and F 2αmmaxQ2 of the photon In leading order and neglecting the muon mass F Bαmma is expected to be identical to the longitudinal structure function F Lαmma The measurement of F Bαmma/F 2αmma is found to be significantly different from zero and to be consistent with the QED prediction

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